Certain lactams, which inhibit β-amyloid peptide release and/or its synthesis, and accordingly, are useful for treating Alzheimer's disease, are described in PCT Application No. PCT/US97/22986.
The present invention provides (N)-((S)-2-hydroxy-3-methyl-butyryl)-1-(L-alaninyl)-(S)-1-amino-3-methyl-2,3,4,5-tetrahydro-1H-3-benzazepin-2-one and the dihydrate thereof, which are useful for inhibiting β-amyloid peptide release and/or its synthesis, and, accordingly, are useful in treating Alzheimer's disease and have advantageous efficacy and safety properties.
Since (N)-((S)-2-hydroxy-3-methyl-butyryl)-1-(L-alaninyl)-(S)-1-amino-3-methyl-2,3,4,5-tetrahydro-1H-3-benzazepin-2-one and the dihydrate thereof are useful for treating Alzheimer's disease, there is a need to produce them as pure, stable, and crystalline forms in order to fulfill exacting pharmaceutical requirements and specifications. In addition, the product should be in a form that is readily filtered, easily dried, and conveniently stored. The novel crystalline anhydrate and dihydrate forms of this invention have suitable properties to be conveniently formulated on a commercial scale in, for example, tablets for oral administration, and have suitable processing and storage properties.